Ishigaki (石垣) was one of four Shimushu-class escort ships built for the Imperial Japanese Navy during World War II.

The ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,200 brake horsepower (3,100 kW) for a speed of 19.7 knots (36.5 km/h; 22.7 mph).

Ishigaki, Koko Maru's escort, sighted the submarine at 3,300 yards (3,000 m) and opened fire with her bow 4.7-inch gun.

Captain Francis Brown of S-44 ordered a crash dive, but Ishigaki scored her first hit on S-44's conning tower before she could submerge.

Perhaps as many as eight men had made it off the submarine; but only Chief Torpedoman's Mate Ernest A. Duva and Radioman Third Class William F. Whitemore were picked up by Ishigaki.